1. Field of the Invention
This invention relates to an inking unit for rotary printing presses with an ink fountain and an ink metering system on an ink fountain roller and, more specifically, to such an inking unit which employs a transfer roller, which .is located between the ink fountain roller and a first distributor roller. The first distributor roller operates in conJunction with other ink rollers, which are located behind the first distributor roller and which transfer the required amount of ink to the printing plate of a plate cylinder.
2. Description of the Prior Art
In inking units of the prior art, an ink fountain roller is operated in conjunction with a vibrator roller, which executes a reciprocating, back-and-forth movement between the ink fountain roller and a first distributor roller. During contact of the vibrator roller with the ink fountain roller, an ink strip of a specified width is applied to the surface of the vibrator roller. When the vibrator roller is pivoted to the first distributor roller, the ink strip is transferred to the first distributor roller. The first distributor roller rotates at the speed of the press, while the ink fountain roller is driven at a lower speed.
A disadvantage of this type of prior art inking unit is that the vibrator roller must have its own control in order to insure that the vibrator roller is properly brought into alternating contact with the adjacent ink fountain and first distributor rollers. The back-and-forth movement results in discontinuous operation and wear of the vibrator roller. An accompanying noise is produced which has a disruptive effect on the operation of the machine. Further, it has been found that a significant amount of labor and equipment is also required to install and control the vibrator roller.